Asymmetric Design Research Articles

Is it me, is it you or is it both of US? Applying the social relations model to disentangle the components of the therapeutic bond

Objective The study investigated the contribution of therapists and patients to the therapeutic bond and their associations (at the within and between levels) to treatment outcome. On this aim, the social relations model (SRM, aimed to analyze dyadic interpersonal data) was implemented. Method A novel design for individual psychotherapy studies was adopted, a many-with-many asymmetrical block dyadic design, in which several patients interact with several therapists. Hierarchical linear models were computed to study through variance partitioning the different components of the SRM and their association to treatment outcome. Results All SRM components (with significant effects at therapist- and patient- within and between levels) resulted in significant contributions to the bond. However, only components at the within- and between-therapist, and within-patient levels resulted in significant associations with outcome. Conclusion Given the dyadic nature of the bond, our results support not only studying and offering clinical training on interpersonal therapeutic skills but also on constant monitoring and feedback of the relationship at the more idiosyncratic level.

Plasmon-Mediated Peroxidase-like Activity on an Asymmetric Nanotube Architecture for Rapid Visual Detection of Bacteria.

Rapid and sensitive detection of bacteria from a complex real media remains a challenge. Herein, we report a visual bacterial sensing assay with excellent specificity, anti-interference ability, and sensitivity based on a surface plasmon resonance (SPR)-enhanced peroxidase (POD) mimetic. The POD mimetic based on Pt nanoparticles (NPs) asymmetrically decorated on Au/TiO2 magnetic nanotubes (Au/Pt/MTNTs) is designed by combining the intrinsic photocatalytic activity of TiO2 and the limited transport depth of light. It is revealed that the localized surface plasmon resonance (LSPR) effect of the asymmetric nanotubes is more effective in facilitating the generation of hot electrons, which are subsequently transferred to Pt and MTNTs, thus greatly promoting the catalytic performance. Using Staphylococcus aureus (S.aureus) as a model of Gram-positive bacteria, the dependence of the colorimetric reaction on the active sites of the POD mimetic is used for the sensing of target bacteria. Owing to the specific recognition between S.aureus and peptide, the fluorescein isothiocyanate (FITC) labeled peptide probes are captured by S.aureus and removed from the Au/Pt/MTNTs, leading to the recovery of POD-like activity and fluorescence emission of S.aureus. Particularly, benefiting from the Au-SPR effect and the magnetic feature of the Au/Pt/MTNTs, the recovery of catalytic activity induced an improved colorimetric assay with a wider linear response for S.aureus qualification and a detection limit of four cells, as well as satisfactory selectivity and feasibility for application in real samples. The plasmon-enhanced POD activity would provide a simple-yet-effective approach to achieve a colorimetric bioassay with high efficiency and sensitivity. This asymmetric design can also be utilized to engineer nanozymes in colorimetric assays for the specific detection of biotoxins, biomarkers, and cancer cells.

Probabilistic calibration of environmental reduction and partial safety factors for the design of reinforced concrete beams strengthened by flax fibre reinforced polymers based on two-factor accelerated degradation tests

The main topic of this article is the probabilistic-based calibration of environmental reduction and safety coefficients for the design of reinforced concrete civil engineering structures repaired or strengthened by externally bonded flax fibre reinforced polymers (FRP). In view of the poor feedback on the durability of flax fibre composite materials used in civil engineering and the impossibility of conducting performance tests over several years, a two-factor accelerated test campaign based on the stimulation of composite degradation by increasing both temperature and humidity conditions was conducted. Flax-FRP (with a bio-based epoxy matrix) laminates and Flax-FRP-strengthened concrete slabs have been exposed over a period of two years to various couplings of temperature (from 20 °C to 60 °C) and humidity (from 50 % of relative humidity to water immersion), according to an asymmetrical Hoke design of experiments. Similar specimens were also exposed to outdoor natural ageing (climate of Lyon, FR) over a period of three years. Series of tests (more than 320 tests) aimed at monitoring the evolution of the degradation of mechanical characteristics (tensile capacity, tensile stiffness, shear strength, pull-off strength) directly associated with the possible modes of failure of structural elements repaired by composites, were carried out on control and aged specimens. A degradation model of these mechanical characteristics considering the competition of two mechanisms - inducing non-monotonic degradation-, and the influence of the temperature and the humidity - through the Eyring model -, was then developed and finally extended to consider the variability of the degradation under different climatic zones. On this basis, a reliability-based approach was adopted to propose environmental reduction and safety coefficients calibrated for Flax-FRP found within four international design guides (Fib bulletin 40, ACI-440, AFGC and TR55 guides). Finally, we showed the necessity to provide adaptable coefficients according to the climatic conditions in which the Flax-FRP elements will be installed.

Engineered subnanochannel ionic diode membranes based on metal–organic frameworks for boosted lithium ion transport and osmotic energy conversion in organic solution

Harvesting Gibbs energy from a salinity gradient of waste organic solutions can not only alleviate the environmental pollution but also provide new energy resources to mitigate the energy shortage. However, the membranes with high ion selectivity, excellent ionic flux, and high-performance power output in organic solutions remain considerably unexplored. Here, we report on the metal–organic framework (MOF) based subnanochannel ionic diode membrane (IDM), comprising a large-area and continuous zeolitic imidazolate framework-8/polystyrene sulfonate membrane and a highly ordered alumina nanochannel membrane, for highly efficient osmotic energy conversion in organic solution. We show that a distinctly asymmetric design of pore sizes, charges, and wettabilities and the numerous highly negatively charged and angstrom-scale window-cavity pore structures in the MOF layer endow the subnanochannel IDM with directional and amplified Li+ ion transport and enhanced selectivity in methanol. Thus, an unprecedented power density of ∼23.4 W/m2 is achieved when a 2 M LiCl-methanol solution is mixed with the pure methanol, 5-times more than the existing value. This work provides significant insights into the use of rectified ion channel-mimetic membranes for achieving ultrafast Li+ ion transport at the confinement and high-performance energy harvesting from organic solutions.

An All-Dielectric Metasurface Polarimeter.

The polarization state of light is a key parameter in many imaging systems. For example, it can image mechanical stress and other physical properties that are not seen with conventional imaging and can also play a central role in quantum sensing. However, polarization is more difficult to image, and polarimetry typically involves several independent measurements with moving parts in the measurement device. Metasurfaces with interleaved designs have demonstrated sensitivity to either linear or circular/elliptical polarization states. Here, we present an all-dielectric meta-polarimeter for direct measurement of any arbitrary polarization state from a single-unit-cell design. By engineering a completely asymmetric design, we obtained a metasurface that can excite eigenmodes of the nanoresonators, thus displaying a unique diffraction pattern for not only any linear polarization state but all elliptical polarization states (and handedness) as well. The unique diffraction patterns are quantified into Stokes parameters with a resolution of 5° and with a polarization state fidelity of up to 99 ± 1%. This holds promise for applications in polarization imaging and quantum state tomography.

Hybrid-plane spectrum slicing for sequentially timed all-optical mapping photography.

Sequentially timed all-optical mapping photography (STAMP) is an effective tool for observing ultrafast and non-repetitive events. In the classical design of STAMP, the spatial resolution of the acquired images is different in two directions, severely limiting the scalability of STAMP. Here, by introducing an asymmetric optical design, we make the slicing mirror locate in the hybrid plane of the system, i.e., the image plane in the direction of the short edge, while the Fourier plane is in the direction of the long edge. This avoids the loss of the high-frequency components of the images and hence offers the possibility to further extend the frame number of the system.

Asymmetric constrained control scheme design with discrete output feedback in unknown robot–environment interaction system

AbstractIn this paper, an overall structure with the asymmetric constrained controller is constructed for human–robot interaction in uncertain environments. The control structure consists of two decoupling loops. In the outer loop, a discrete output feedback adaptive dynamics programing (OPFB ADP) algorithm is proposed to deal with the problems of unknown environment dynamic and unobservable environment position. Besides, a discount factor is added to the discrete OPFB ADP algorithm to improve the convergence speed. In the inner loop, a constrained controller is developed on the basis of asymmetric barrier Lyapunov function, and a neural network method is applied to approximate the dynamic characteristics of the uncertain system model. By utilizing this controller, the robot can track the prescribed trajectory precisely within a security boundary. Simulation and experimental results demonstrate the effectiveness of the proposed controller.

Analysis of Self-propulsion Test for Propeller KP-505 with and without Pre-Swirl Stator

In recent times, environmental issues have become a major concern. The installation of Energy Saving Device (ESD) on ships is an alternative method developed to reduce energy use. One type of ESD that is widely used is the installation of a Pre-Swirl Stator (PSS). PSS consists of stator blades mounted in front of the propeller to regulate flow before entering the propeller. This paper describes the effect of PSS installation on the hull of a KP-505 propeller. The asymmetrical PSS design was developed with three blades on the port side and one on the starboard side. The analysis was carried out to obtain the Propulsive Coefficient (PC). The research was conducted using Computational Fluid Dynamic (CFD)-based simulation. The simulation results show that the addition of PSS increases the ship’s resistance up to 4%. However, the PC has also increased significantly up to 10.3, so it can reduce power requirements by up to 5.6%.

The Separation-Recombination Dipole MBRD for the High-Luminosity LHC: From Prototype to Series

The next upgrade for the Large Hadron Collider (LHC), called High-Luminosity LHC, has the aim of increasing the rate of collisions of the accelerator by a factor of ten. To achieve this goal, the dipole and quadrupole magnets before and after the interaction region of the ATLAS and CMS experiments will be replaced. One of these is the separation-recombination dipole MBRD, which features a target integral magnetic field of 35 T <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula> m in a double aperture of 105 mm, obtained with a magnetic field of 4.5 T along a magnetic length of 7.78 m. One of the main challenges in the development of this magnet is the fact that the two apertures must have the same polarity and this causes a magnetic cross-talk between them. Because of this, it has been necessary to develop a left/right asymmetric aperture coil design for the coils to compensate this effect, that would have generated unwanted multipoles. Another problem related to the same polarity in the two apertures is a repulsive Lorentz force between them, which has been managed through the implementation of Al alloy sleeves assembled around the two collared apertures. The design was carried out in the framework of a CERN-INFN Genova agreement and the construction is ongoing in the industry ASG Superconductors. The 1.6 m long model was built and successfully cold tested, followed by the construction of a full-length prototype, recently delivered to CERN, while the construction of the series of 6 magnets is foreseen to be started at the beginning of 2022. This contribution will describe the prototype assembly status, also covering the field quality (FQ) aspect, discussing the results of the warm magnetic measurements at ASG and their implication in the design of the series in terms of harmonic content.

Asymmetric Electrospun Nanofiber Composed Of Polycaprolactone, Chitosan, and Curcumin To Promote Chronic Wound Healing

Chronic wounds are a growing medical issue around the world, with 2.4 - 4.5 million people afflicted in the United States alone. The condition currently makes up 2-3% of healthcare costs for developed countries, and this number is expected to increase as chronic wound-causing problems, like diabetes, grow in prevalence. Due to the lack of effective wound dressings, chronic wounds face a higher risk for bacterial infection and express high morbidity and mortality rates. Many current dressings are homogeneous and fail to account for the complexities of the different layers of skin. Alternatively, asymmetric electrospun nanofibers have a bilayer design that corresponds to the skin’s dermis and epidermis. We intend to demonstrate that an asymmetric electrospun nanofiber composed of polycaprolactone (PCL), chitosan (CS), and curcumin (Cur) can be utilized as a chronic wound dressing. These three biodegradable and biocompatible components were applied in an asymmetric design to mimic the protective epidermis and porous dermis. Upon electrospinning our asymmetric nanofiber and running it through a scanning electron microscope, we found that our hydrophobic PCL layer had a low porosity (52.16%) and thin nanofibers (281.82 nm), while our hydrophilic PCL/CS/Cur layer had a high porosity (61.18%) and thick nanofibers (425.54 nm). Our asymmetric nanofiber was also more effective at resisting bacterial permeation than the homogeneous PCL nanofiber. Our results highlight the superiority of asymmetric membranes for resisting bacterial infection and suggest that with further experimentation, we can establish our nanofiber as a viable wound dressing.

Asymmetric point-to-multipoint coherent architecture with a frequency aliasing recovery algorithm for cost-constraint short-reach access networks.

An asymmetric point-to-multipoint (PTMP) coherent architecture combined with a frequency aliasing recovery (FAR) algorithm is proposed for cost-constraint short-reach access networks. In this architecture, the uplink transmitters are simplified significantly with the uplink dual-polarization four-level pulse amplitude modulation (DP-PAM4) and downlink DP quadrature phase shift keying (DP-QPSK) asymmetric transmission design. Digital to analog converters (DACs) and radio frequency (RF) drivers are reduced by half, and in-phase and quadrature modulators (IQMs) are replaced by Mach-Zehnder modulators (MZMs), saving four MZ interferometers (MZIs). Furthermore, based on the asymmetric architecture, the FAR algorithm can recover signals from frequency aliasing caused by frequency offset (FO), even when half of the signal spectrum is aliased. This algorithm enables the asymmetric architecture to narrow down guard bands between subcarriers or even overlap the subcarriers, saving the receiver bandwidth at the aggregation/hub side. The performance of the asymmetric uplink DP-PAM4 transmission with the FAR algorithm is evaluated in both simualations and experiments. The effects of laser linewidths and IQ skew on the performance of the FAR algorithm are also analyzed. Simulation results show the algorithm can recover 16 Gbaud and 32 Gbaud signal from 8 GHz and 16 GHz aliasing, respectively. In the experiments with 10 km fiber transmissions, the FAR algorithm can recover 10 Gbaud signals from 5 GHz frequency aliasing, saving about 20.83% of the total receiver bandwidth in a 2-subcarrier system.

A two-dimensional electromagnetic vibration energy harvester with variable stiffness

This work investigates the performance of an electromagnetic vibration harvester for two-dimensional vibrations with variable magnetic stiffness and electromagnetic damping. The device consists of a free-to-move cylindrical magnetic structure with a set of bearings located on top and bottom, a couple of coils located on top and bottom of the device and finally a fixed system of disk-shaped magnets placed inside a ring holder. The number of disk-shaped magnets in the ring holder can be varied to change the magnetic stiffness of the system. The performance of the device is characterized experimentally for nine different configurations of disk-shaped magnets, exploring both symmetric and asymmetric designs. Using an XY-shaker to vibrate the system in two dimensions in frequencies from 1 Hz to 10 Hz and with motion amplitude of 2 mm on both axes, a maximum power of 27 mW was harvested. This occurs for an asymmetric device, i.e. with different magnetic stiffnesses along its two axis. For symmetric devices the power is lower by a factor of two. Finally, varying the electromagnetic damping, which is controlled by varying the coil dimensions, can further increase the power to 42 mW.

Cross-linker design determines microtubule network organization by opposing motors

During cell division, cross-linking motors determine the architecture of the spindle, a dynamic microtubule network that segregates the chromosomes in eukaryotes. It is unclear how motors with opposite directionality coordinate to drive both contractile and extensile behaviors in the spindle. Particularly, the impact of different cross-linker designs on network self-organization is not understood, limiting our understanding of self-organizing structures in cells but also our ability to engineer new active materials. Here, we use experiment and theory to examine active microtubule networks driven by mixtures of motors with opposite directionality and different cross-linker design. We find that although the kinesin-14 HSET causes network contraction when dominant, it can also assist the opposing kinesin-5 KIF11 to generate extensile networks. This bifunctionality results from HSET's asymmetric design, distinct from symmetric KIF11. These findings expand the set of rules underlying patterning of active microtubule assemblies and allow a better understanding of motor cooperation in the spindle.

A Novel Low-Cost Three-Dimensional Printed Brace Design Method for Early Onset Scoliosis

Abstract Early onset scoliosis (EOS) is a type of spine deformity that presents before 10 years of age. The biomechanical properties in scoliosis have been found to be different, especially in the case of the concave and convex paravertebral muscles. Based on this fact, a novel three-dimensional (3D) printed patient-specific asymmetric stiffness brace design method is proposed in this paper, aiming to provide asymmetric stiffness to match “imbalanced” biomechanical properties of the concave and convex paravertebral muscles, respectively, and treat EOS by applying the block-structure brace. A 3D computer aided design draft model of the brace contour was implemented from 3D scanning. The asymmetric stiffness block-structure brace was designed in Rhinoceros and the finite element (FE) model was imported into abaqus. FE simulation was employed to study the mechanical characteristics of the brace, which provided a quantitative index for the imbalanced property of brace stiffness. The results of the FE simulation showed that the stiffnesses of the concave and convex sides were 145.88 N/mm and 35.95 N/mm, respectively. The block-structure brace was fabricated using 3D printing. Asymmetric stiffness was evaluated by corrective force measurements, which were obtained from a thin-film pressure sensor equipped on the brace. The patient-specific asymmetric stiffness brace was applied to clinical practice in a one-year-old EOS patient. A novel low-cost 3D printed brace design method for EOS was proposed in this study that could potentially be useful in patient treatment acceptance.

Double‐Cable Conjugated Polymers with Pendent Near‐Infrared Electron Acceptors for Single‐Component Organic Solar Cells

AbstractDouble‐cable conjugated polymers with near‐infrared (NIR) electron acceptors are synthesized for use in single‐component organic solar cells (SCOSCs). Through the development of a judicious synthetic pathway, the highly sensitive nature of the 2‐(3‐oxo‐2,3‐dihydroinden‐1‐ylidene)malononitrile (IC)‐based electron acceptors in basic and protonic solvents is overcome. In addition, an asymmetric design motif is adopted to optimize the packing of donor and acceptor segments, enhancing charge separation efficiency. As such, the new double‐cable polymers are successfully applied in SCOSCs, providing an efficiency of over 10 % with a broad photo response from 300 to 850 nm and exhibiting excellent thermal/light stability. These results demonstrate the powerful design of NIR‐acceptor‐based double‐cable polymers and will enable SCOSCs to enter a new stage.

Double-Cable Conjugated Polymers with Pendent Near-Infrared Electron Acceptors for Single-Component Organic Solar Cells.

Double-cable conjugated polymers with near-infrared (NIR) electron acceptors are synthesized for use in single-component organic solar cells (SCOSCs). Through the development of a judicious synthetic pathway, the highly sensitive nature of the 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC)-based electron acceptors in basic and protonic solvents is overcome. In addition, an asymmetric design motif is adopted to optimize the packing of donor and acceptor segments, enhancing charge separation efficiency. As such, the new double-cable polymers are successfully applied in SCOSCs, providing an efficiency of over 10 % with a broad photo response from 300 to 850 nm and exhibiting excellent thermal/light stability. These results demonstrate the powerful design of NIR-acceptor-based double-cable polymers and will enable SCOSCs to enter a new stage.

Helicon Injected Inertial Plasma Electrostatic Rocket

The Helicon Injected Inertial Plasma Electrostatic Rocket (HIIPER) is a space propulsion system developed at the University of Illinois Urbana-Champaign. The HIIPER couples a helicon tube with an inertial electrostatic confinement (IEC) fusion system. Its operating principle involves a helicon ionization stage followed by an electrostatic grid (IEC cathode grid) extraction stage. The helicon setup used in the HIIPER is modified to include a helicon bias grid at the upstream end of the tube. This grid is applied with a positive direct-current voltage to increase the plasma potential and the most probable ion energy of the plasma injected into the IEC fusion chamber. The IEC cathode grid in the HIIPER uses an innovative asymmetric design, graphically depicted through a computational model, that ejects a stream of electrons that accelerate the exhaust ions and simultaneously neutralize the exhaust jet. The model is also used to plot ion trajectories inside the HIIPER to identify any wall collision losses. A separate numerical study was undertaken to show augmentation of plasma kinetic energy on adding a magnetic nozzle as the final propulsion stage of the HIIPER. Experimental results were used to establish a relation between the input parameters and the ion density of the resulting plasma. Langmuir probe measurements were performed at two locations to validate corresponding computational results, indicating ion losses due to ion-wall collisions inside the helicon-IEC coupling. The results in this study add to the proof of concept of the HIIPER and allow for designing an upgrade of the propulsion system. Increasing thrust while maintaining plasma densities between 1017 and 1018 throughout the system is the current aim of HIIPER research. This study summarizes the various performance parameters of the propulsion system, along with a discussion of ongoing research and future scope.

Asymmetric sparse telescope

We designed and built a novel model of a deployed space telescope which can reliably align its segments to achieve the finest possible resolution. An asymmetric design of both the segment shapes and their pupil locations were tested in simulation and experiment. We optimised the sparse aperture for better spatial frequency coverage and for smoother images with less artifacts. The unique segment shapes allow for an easier identification and alignment, and the feedback is based only upon the focal image. The autonomous alignment and fine tuning are governed by mechanical simplicity and reliability.

Homochiral Chemistry Strategy To Trigger Dielectric Switching and Second-Harmonic Generation Response on Spirocyclic Derivatives.

Organic-inorganic hybrid materials with switchable properties have significant potential applications in intelligent devices. There are some conventional ways to obtain optical and/or electric multiple responses, such as asymmetric design, chirality, doping, and structural dimension in hybrid materials. Among them, the homochirality strategy is one of the best ways to regulate the molecular structure and symmetry, thereby ensuring second-harmonic generation (SHG) and dielectric dual response characteristics. Here, we report a homochiral design strategy to obtain noncentrosymmetric [R-(HASD)][Cd(SCN)3] (HASD = 7-hydroxy-5-azaspiro[4.5]decan) and [S-(HASD)][Cd(SCN)3]; [Rac-(HASD)][Cd(SCN)3] was also synthesized as a comparative experiment to illustrate the relationship between structural chirality and physical properties. With the help of homochiral regulation, the SHG response is excited and dielectric phase transition temperature (Tc) is also highly improved. In addition, both the optical SHG and dielectric phase change show an optical/electric switchable response. This work is of great significance for the further exploration of multifunctional molecular switching materials through homochiral chemistry.

Enhanced electro-Fenton oxidation by introducing three-phase interface with simultaneous optimization of O2 and pollutant transfer for effective tetracycline hydrochloride removal

Mass transfer plays a dominating role in electro-Fenton (EF) system, where the transportations of gaseous O2 and dissolved pollutant were difficult to simultaneously optimize when using conventionally hydrophilic or hydrophobic electrodes (HIE/HOE). To overcome this difficulty, three-phase interface (TPI) was successfully introduced into sandwich electrode (SE) via an asymmetrical wettability design of hydrophilic catalyst on both sides of three-dimensional hydrophobic substrate. With the help of TPI in SE body, the rapid gaseous O2 transfer process led to the best OH generation of 536.4 μM, over 9 times than HIE (59.4 μM) with dissolved-O2 transfer limitation. Meanwhile, due to a large electrochemically-active area from hydrophilic catalyst layer, more exposed sites at SE surface could availably electro-adsorb 32.0% tetracycline hydrochloride (TC), ∼3.7 times than HOE with TC transfer restriction. Thanks to simultaneous optimization of O2 and pollutant transfer processes, the TPI-rich SE achieved an excellent TC mineralization of 68.0% (removal of 93.3%), far more than 9.3% of HIE and 14.7% of HOE. Therefore, this study paved an ingenious approach to mitigate two-phase (gas/liquid) transfer limitation in EF system for effective organic pollutants degradation.